A 40-year-old man was killed in a single-car crash in Capitol Hill early Friday morning, D.C. police said.

The accident took place near Fourth Street and Massachusetts Avenue NE shortly after 5 a.m.

The man, whose identity has not been released, was the only victim involved in the crash. He was taken to a hospital, where he was pronounced dead, police said.

The cause of the accident is still unknown, according to police, who shut down the 300 block of Fourth Street to investigate.